Quantification of Chaoborus and small fish by mobile upward-looking echosounding
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60077344%3A_____%2F19%3A00504821" target="_blank" >RIV/60077344:_____/19:00504821 - isvavai.cz</a>
Alternative codes found
RIV/60076658:12310/19:43899196
Result on the web
<a href="https://www.jlimnol.it/index.php/jlimnol/article/view/jlimnol.2018.1837/1508" target="_blank" >https://www.jlimnol.it/index.php/jlimnol/article/view/jlimnol.2018.1837/1508</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.4081/jlimnol.2018.1837" target="_blank" >10.4081/jlimnol.2018.1837</a>
Alternative languages
Result language
angličtina
Original language name
Quantification of Chaoborus and small fish by mobile upward-looking echosounding
Original language description
Chaoborus larvae inhabit frequently the water column of lakes, when they can be mistaken for small fish. Because larvae ascend up to the blind zone of downward-looking echo sounding at night, quantitative acoustic estimation of them is possible only with upward-looking approach. For this reason, the mobile hydroacoustic upward-looking system (120 and 38 kHz split-beam echosounder) in combination with a direct catch method (trawling) was tested to investigate the night community of invertebrates and juvenile fish in the surface layer of the Rimov reservoir (Czech Republic). In the target strength range of invertebrates (smaller than59 dB), the 38 kHz echosounder recorded only a small proportion of targets while the 120 kHz echosounder recorded distinct peaks corresponding to high densities of Chaoborus (target strength, TS range70 to60 dB, average TS66 to64 dB). At 120 kHz frequency, the TS distribution of smaller cohort of juvenile fish (<25 mm in length) overlapped the TS-distribution of Chaoborus. The number of these smaller juvenile fish was so small compared with the number of Chaoborus that they did not seriously bias acoustic Chaoborus estimate. The correlation between the density of Chaoborus with small contamination of juvenile fish larvae from trawling and acoustic recording made with the 120 kHz echosounder was high (R-2=0.88), but the acoustic densities from trace counting appeared to underestimate Chaoborus abundance when the density was >1.5 ind.m(-3).
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
40103 - Fishery
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2019
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Limnology
ISSN
1129-5767
e-ISSN
—
Volume of the periodical
78
Issue of the periodical within the volume
1
Country of publishing house
IT - ITALY
Number of pages
11
Pages from-to
60-70
UT code for WoS article
000463363000006
EID of the result in the Scopus database
2-s2.0-85065888914